Governing mechanism for turbines.



PATENTED DEC, 3

APPLICATION FILED JUNEI, 1905.

/n ventor":

Witnesses:

eder/k Samue/son,

toll is connected by a pipe or passage with I UNITED s ATEs PATENT OFFFREDERICK SAMUELSON, OF RUGBY, ENGLAND ASSIGNOR TO GENERAL ELEOTBIGOOMPANY, A CORPORATION OF NEW YORK.

GOVERNING MECHANISM FORTURBINES.

Specification of Letters Patent.

Patented Dec. 3, 1907.

Application filed June 1, 1 905. Serial 1%. 263.212-

.To. all whom it may concern:

' Be it known that I, FREDERICK SAMUEL- the following is aspecification.

This invention relates to the governing of elastic fluid turbines of thetype describe'd in British Patent, No. 19,247 of 1896 in which thegoverning is eiiected by arying the quantity of steam delivered by theinlet nozzle or nozzles without change in the ratio' of expansioneffected in the nozzles. In such turbines in order to work with themaximum economy under varying loads it is desirable to vary the capacityof the steam passage in the various stages of the machine "111 proortion to the variation in the qiiantity o steam admitted to the inletnozzles for each load.

The purpose of this invention is to provide means for automaticallyaccomplishing this object and to this end it'consists in providing motoroperated valves controlling a portion of the inlets to one or more ofthe stages after the first and in causing these valves to be actuatedautomatically so as to maintain the desired pressures within thedifferent stages ofthe machine. 4' I v v In carrying this invention intoeffect ac-' cording to one modification as applied to a tWO ,Stageturbine, I provide a number of slide valves. controlling a ortion of theinlet assageto the nozzles o the second stage. Each of these valves isnormally held closed by means of a spring operating on one side of *apiston working in a closed'chamber fitted to the side of the turbinecasing. The part of the chamberonthe other side of eachpisthevalve-controlled supplly chamber of one ormore inl'et nozzles of t efirst stage'of the machine. The number of valves. provided on the secondstage is arranged in accordance v with the load conditions to befulfilled in practice."

Accordin to another modification, 'instead of a .shde valvefor-controlling the inlet nozzles of the second stage I employ a istonvalve. This .valve works in a chain )er or casingattached to the sideofthe turbine and 7 controls -a passage between the exhaust of the firststage and a portion of the inlet nozzle supply chamber of the secondstage.

, England, haveinvented cer-. 5 tam new an useful Improvements nGovermng Mechamsms for Turbines, of which binc,

This valve works verticallya'nd in its closed position is held upagainst its seat at the end .of a ring opening forming part of saidpassage by means of a spring. The spring is inclosed within a removablecap through the top of which an adjusting screw passes by means of whichthe spring pressure nay be regulated. i This cap also enables the valveto be readily removed from. its casing for examination or repair.

On the upper part-of the valve chamber;- directly above the/valve, isalso fitted a cap forming the cylinder fora small piston the stem ofwhich abuts against the top of the piston valve. The upper end of thischamber is connected to the supply chamber of an inlet nozzle or nozzlesection by means of a pipe.

- When the steam supply to this'chamber is cut off the piston valve isheld in its closed position by means of the spring but when steam isadmitted to the first stage nozzlethe pressure passes to the smallcylinder at the-top of the second stage valve casing,

forcing the small piston downwards and.

thereby opening the piston valve against the force of its controllingspring. Steam is thus admitted through the passage'from the first stageto the inletnozzlesof the second stage controlled by the piston valve,in accordance with the load condition.

The accompanying drawings illustrate means for carrying my inventioninto effect as ap lied to a two stage elastic fluid turure 1 being asectional view of part of a tur ine in which the admission of fluid tothe second stage is controlled by a valve operated by fluid from theinlet nozzle of the first stage; Fig. 2 is a similar view of a turbinein which the admission of fluid to. the

second stage is controlled bya iston valve which besidesbein o erated ythe high pressure fluid as int c st modification'may. also on emergencybe operated by the exhaust fluid from the first stage and Fig. 3 is alan view of a vertical-shaft turbine showing the arrangement of theadmission and stagevalve's'. 3

In carryin my invention into efiect according to t e modificationillustrated in Fig. 1-, I provide an elastic 'fluid turbine ofthe typeabove referred to in which the velocity of .thefluid is extracted in twostages and caused to operate on two moving elements or wheels 1 and 2arranged in separate chambers. Steam or other elastic fluid is admittedto the first stage through an inlet valve. 3 0i any well-known type andpasses through the inlet nozzle f'to the wheel 1. After having passedtin -thigh and aperated on the wheel orwheels in the first stage thefluid passes through the nozzles?) into the second stage. Some of thesenozzles 5 however are controlled by valves such as the slide valve 6normally held closed by the action of a compression spring 7 surroundingthe valve rod 8. p This valve rod passes into a hollow cylindricalcasing 9 secured in any suitable manner in or formed integral with theturbine casing 10 and provided with a closing cap l1. Mounted withinthis cap on the 'end of the valve rod Sis a. iston 12 which slidinglyfits the interior of t 1e casing 9 or cap 11 and against the inner sideof which the spring 7 abuts so as normally to hold the valve 6 in itsclosed position. The interior of the casing 011 the opposite side of thepiston from the spring is in communication through the pipe 13 with thefluid space 14 between the inlet valve 3 and the nozzle 4.01 the firststage. I 1 v It will be seen'from the above description that when theinlet valve 3 is closed, no fluid can pass through the pipe 13 to theouter side of the piston 12 and the spring will hold the piston in itsoutermost position there- .by maintaining the valve 6 closed. ithowever, the load on the turbine/be increased-so as to cause the valve 3to open, some of the working fluid will pass through the pipe 13 to theinterior of the casing 9 on the outer side of the piston. This fluidacting on the piston overcomes the pressure of the spring and causes thevalve to uncover or partly uncover the inlet nozzle 5 of the secondstage thereby -accommodating for the increased volume of. fluid admittedto the first stage,

by the opening of the valve 3, by providing increased passage area tothe second stage. Itis to be understood that the valve 3 may onlycontrol the admission of fluid to one inlet nozzle or'to agroup ofnozzles, and similarly, the valve6 may also control, one or a group ofnozzles admitting fluid to the second stage of the turbine.

In the modification illustrated in Fig. 2,

' the valve controlling the admission of fluid from the first to thesecond stage is provided with a separate housing or casin 15 secured tothe turbine casing. Inside t 's casing is a spring pressed piston valve16 which is adapted to control the passage of fluid through a port 17leading to the inlet'nozzles of the second stage. The upper end of thispiston valve is directly in communication with the exhaust side of thefirst stage of the turbine through a port or passage 18 but the springcontrolling it is so adjusted that normally it maintains the pistonvalve on its seat against the pressure of the exhaust. Shouldhowever'the pressure of the.

exhaust in the first stage rise beyond a predetermined amount the springwill be overcome causing the piston valve to move downwards and touncover the passage to the nozzles oi" the second stage, therebyrelieving the pressure of the exhaust Mounted. directly in line 'withthe piston valve 16 is a cap or cylindrical casing 1.9 the lower end ofwhich is open to the passage 18 and the made to open at anypredetermined exhaustpressure. The operation of this modification 18practically the same as zzescrihco above with reference to the firstmodification izz--- When valve 3 is opened toadmii more fluid: to thenozzles of the first stage. some of the fluid passes through the pipe 13to the upper side .of the piston 20 causing it to move downward andwithit the piston valve us through the pressure of the piston stem 21 onits upper side, therelry uncovering the port 17 and allowing fluid topass from the exhaust'side-of the first stage through passage 1S andport 17 to the inlet nozzles ol the second stage.

Although I have descrihed my invention as applied to a two stage machineit villit'lze obvious. that it is equafly appiicahlc to the control ofthe various stages of a machine having more than two stages: it wizl further he olivious that without departing from the spirit of the inventioninstead of actuating the stage controtling 'vaires 13y fluid pressurethese valves may he otherwise automatically actuated. For example wherethe ya ives controllin the nozzles on the first stage are operateu byetectromagncts. S1111]- lar electromagnets may he conveniently employedfor tiperating the valves lretween stages, the eiectromagnets of thefirst and succeeding stage valves lreing interlocked m a manner obviousto those skilled in the art.

In Fig. 3, which shows a plan view of a vertical-shaft turliine, 22represents the governor-inclosing dome directly over the main shaft.Steam or other elastic fluid is admitted to the turbine by the branchedconduit 23. Steam from the conduit enters the chests 24 containin theindividual and sep arately actuated va.ves 3 which regulate theadmission of motive fluid to the first-stage nozzles 4. 25 and 26represent stage valves locatedi'n a-common casing which control thepassage of steam or other motive fluid from the first to the secondstage. These valves may be located directly under the admission valvesor displaced therefrom. 27 and 28 represent stage valves located inindependent casings Which control the passage The " and in what mannerthe same is to be performed, Ideclare that what I claim is 1 motivefluid through one of the stages, and a 'seat.

between two or more stages, said valve or va'l ves operatingautomatically 1n accordv of the first stage, substantially as described.

tiallyas described.

- creased or decreased as the conditions of servsaid valve receiving itsoperating fluid when hereinbefore referred to, a motor-operated of steambetween successive sta es, as for The number of stages providedwiththese valves can be inice'demand. Having now particularly describedand ascertained the nature of my said invention 1, A turbine dividedinto stages with wheel. buckets for the sta es, in combination th avalve for controlling the passage of fluid actuated valve controllingthe passage of motlve fluid through another stage, the

the' first mentioned valve moves from its 2. In a .multi-stage turbineof the type valve or valves controlling the fluid passage 'aiicje withthe pressure within the valve controlled supply chamber of a nozzle ornozzles 3. in a multi-stage turbine, of the type hereinbefore referredto, a motor-operated valve or valves controlling the fluid passagebetween stages said valve or valves being normally held in the closedposition by means of a spring and opened by means offluid pressureadmitted from the supply chamber of a nozzle or nozzles of the firststage, substan- 4. A turbine comprising wheel buckets andfluid-discharging devices arranged in stages, in combination with astage valve which is normally operated by hi h-pressure fluid but whichopens automatica ly upon an increase in stage pressure above a certainamount. 5. A turbine comprising wheel buckets and fluiddischargingdevlces arranged in stages, a stage valve which opens under apredetermined increase in stage pressure, a means for normally openingsaid valve by motive fluidfof a pressure above that of the stage, and ameans for controlling the action of the motive fluid of higher pressure.

6. A turbine divided into stages, with wheel buckets and dischargingdevices fOll wheel buckets and dischargin.

' mentioned valves move from their seat.

7. A turbine divided into stages, with devices for the stages, admissionvalves 'or the hi hpressure stage, valves between stages whlch arenormally governed by the admission valves, the said stage valves alsoopening in response to a definite increase in stage pressure, and meansopposing the opening of the stage valves and causing them to operatesuccessively.

8. A turbine comprising wheel buckets and fluid-discharging devicesarranged in stages, in combination with admission valves, stage valvesautomatically opening under abnormal stage pressure, means responding tohigh pressure for normally opening the stage valves, and a device forclosing each of the stage valves irrespective of whether it is opened bystage or high pressure.

9. A turbine divided into stages with wheel buckets for the stages, incombination with a valve controlling the passage of motive fluid througha stage, a second valve controlling the passage of motive fluid throughanother stage, a fluid actuated motor for moving the second valve in onedirection, a mechanical motor for moving it in the opposite direction,and a conduit leading to the fluid actuated motor which i s controlledby the first mentioned valve.

10. A turbine divided into stages with wheel buckets for the stages, incombination with a nozzle, a controlling valve therefor, a stage nozzle,a stage valve controlling it, a fluid actuated motor for moving thestage valve in one direction, a spring for moving it in the oppositedirection, and a conduit that communicates with the motor and the first

